The present invention relates to a method for producing an intermediate product made of a fiber-reinforced composite.
Stiffened panels made of fiber-reinforced composites (prepregs) are light in weight and high in strength, to have been widely used for automobiles, ships, aircrafts, etc. The stiffened panels are generally produced by placing members for a skin and stiffeners (stringers and frames) each made of a fiber-reinforced composite on a forming tool to prepare an assembly, and by forming the assembly by heating under a pressure while using a pressure bag, etc. To produce a stiffened panel having a reduced weight and improved dimensional and positional accuracy with excellent formability, it is preferred that members composing the stiffeners are preformed to obtain intermediate products beforehand, and the intermediate products are arranged on a skin and then integrated therewith to produce a final product.
Conventionally, the above-mentioned intermediate products have been produced by a method comprising the steps of: cutting fiber-reinforced composites many times to obtain desired lamination structures, respectively; laminating the fiber-reinforced composites on a forming tool to provide a laminate; and forming the laminate. However, this method necessitates complicated works, in particular, lamination of the fiber-reinforced composites on the forming tool is achieved by handwork, thereby requiring much effort.